There shall be provided on the same site with any use except as modified by § 36-25.3, off-street parking spaces for vehicles in accordance with the requirements herein. Where existing buildings not now meeting these requirements are proposed to be enlarged or increased in capacity in excess of ten (10%) percent, in any district except a single-family district, off-street parking shall be provided as required herein for the entire floor area of the structure.

Floor Area. "Floor Area" in the case of office, merchandising or service types of uses means the gross area used or intended to be used by tenants, or for service to the public as customers, patrons, clients, or patients including areas occupied by fixtures and equipment used for display or sales of merchandise. It does not include areas used principally for non-public purposes, such as storage and incidental repair.